Whole-body transmission x-ray scanner and methods for whole-body scanning

ABSTRACT

A whole-body transmission x-ray scanner includes an x-ray source, an x-ray camera, a controller, and a positioner aligning the source and camera to point x-rays towards the camera and moving the source and camera synchronously to scan and acquire radiographic images of an object located therebetween. The positioner includes a closed-loop cable alignment assembly fixed to the source and to the camera to maintain alignment of the source and camera during a scanning mode in which the source and camera move from one end of the object to another end. The positioner includes a motor controlled by the controller, a bi-directional crossover slide track bearing assembly connected to the source, and a conveyor connected to the motor and bearing assembly such that, actuation of the motor by the controller moves the slide track bearing assembly in a loop that correspondingly move the source and camera along a single linear axis.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application Ser.No. 62/572,065, filed on Oct. 13, 2017, and 62/615,746, filed on Jan.10, 2018, the entire disclosures of which are hereby incorporated hereinby reference in their entireties.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

FIELD OF THE INVENTION

The present systems, apparatuses, and methods lie in the field of x-rayscanning. The present disclosure relates generally to an x-ray scannerand methods of x-ray scanning that produce radiographic images of thewhole human body. The scanner produces whole-body transmissionradiographic images of a person in a standing or prone position whilethe person remains stationary. Applications for whole-body radiographicimaging include contraband detection and medical diagnosis, for example.Other applications include imaging objects such as cargo and personaleffects for security reasons. The systems, apparatuses, and methodsincorporate a collimated x-ray source, a linear x-ray camera, a userinterface, and a positioner that moves the x-ray source and x-ray camerain a synchronous motion to scan and acquire radiographic images. Anexemplary embodiment of a positioner incorporates asingle-motor-conveyor-belt-drive with a bi-directional crossover bearingassembly, a closed-looped-cable-alignment system, an operator controlstation, and a selectable manual or continuous x-ray scanning. In amanual mode, the scan mode passes through one cycle and stops until anext scan is executed. In a continuous mode, the scan mode runs in acontinuous loop and x-rays will be generated when the x-ray tube andcamera are in a downward motion. The x-ray stops when the x-ray tube andcamera reach the bottom and, then, the system continues to move,allowing the person who was just scanned to move out of the scanningarea and the next person to enter and step into position so that, whenthe system is ready for the next x-ray scan, the next person is inposition for scanning.

BACKGROUND OF THE INVENTION

Transmission x-ray scanner designs for whole-body radiographic imaginghave been described in the patent literature for over fifty years. Onesuch system is described in U.S. Pat. No. 3,101,407 to Shipman, whichissued on Aug. 20, 1963. In Shipman, the source and the camera are moveddirectly with cables and pulleys connected to a motor. Scanning startsfrom a parked stop, accelerates to a scanning speed, and thendecelerates to a parked stop. This change in motion is repeated for thenext scan. This movement introduces error into the detected image andproduces motion artifacts in the image. The scanner taught by Shipmansuffers from several limitations. One of the primary limitations is thecomplexity of the positioner (drive and cable mechanisms) used to movethe x-ray source and linear x-ray camera and support the person beingscanned. Such a drive-and-cable system is too complex to be practical orcost effective. The system also was designed to move slowly. Anotherlimitation is that the motion of the x-ray source and linear x-raycamera can only move in one direction at a time, either up or down. Oncethe source/camera arrives at a limit of travel in either direction, itmust come to a full stop and reverse direction. This creates a need toaccelerate the x-ray source and linear x-ray camera when starting andstopping the scan, which also introduces the problem of gear backlashthat must be compensated for when reversing the motor direction.

Another prior art system is described in U.S. Pat. No. 8,477,902 to Liet al., issued on Jul. 2, 2013. This patent describes a system havingtwo independent vertical towers: one tower for the x-ray source and asecond tower for a linear x-ray camera. The x-ray source and the linearx-ray camera are each driven by separate motors and are kept inalignment by a phasemeter. This technology has limitations with respectto vertical travel and maintaining alignment. More specifically, themotors require a start and stop distance that has effect on the scanningtravel distance that can be accomplished at a constant speed. In thisdesign, motor backlash is an issue and must be addressed and compensatedfor when reversing direction.

SUMMARY OF THE INVENTION

The systems, apparatuses, and methods described provide a whole-bodytransmission x-ray scanner that overcomes the hereinafore-mentioneddisadvantages of the heretofore-known devices and methods of thisgeneral type and that provide such features with a novel design thatgreatly simplifies the structure for synchronously scanning the x-raysource and the linear x-ray camera to image a stationary person using apositioner comprising a single motor-conveyor-loop chain/belt-drive, anovel bi-directional crossover bearing slide track, and a closed loopcable alignment system.

The positioner employs a vertical conveyor drive system connected to thex-ray source by a novel bi-directional crossover slide bearingmechanism. Use of the bi-directional crossover slide bearing mechanismpermits the x-ray source to move up and down without having tocompensate for the start or stop motor acceleration and lag and withoutchanging the direction of the drive motor from up to down motion and,therefore, eliminates all need for motor-drive backlash compensation. Atthe start of a scan, the distance traveled during acceleration of themotor drive is best compensated for when the scan direction is downwardso that there is room to allow the motor to come up to a constantvelocity before exposing the person. A closed-loop cable systemconnecting the x-ray source to the linear x-ray camera remains inconstant tension and, therefore, moves the linear x-ray camera in asynchronous motion to stay in alignment with the x-ray source. Theclosed-loop cable alignment system also keeps the x-ray source assemblyand the x-ray camera assembly stable by damping vibration while movinglimiting motion artifacts as well as venetian blind effect.Counterweights are used to balance the load so that, when the x-raysource and x-ray camera move up and down together, they present the sameresistance to the drive motor in either direction, thereby placing lessload-stress on the motor drive assemblies.

With the foregoing and other objects in view, there is provided, awhole-body transmission x-ray scanner comprising a collimated x-raysource emitting x-rays, a linear x-ray camera configured to detect thex-rays, a controller, and a positioner that aligns the x-ray source andthe x-ray camera to point the emitted x-rays towards the x-ray cameraand moves the x-ray source and the x-ray camera synchronously to scanand acquire radiographic images of an object located between the x-raysource and the x-ray camera, the positioner comprising a closed-loopcable alignment assembly fixed to the x-ray source and to the linearx-ray camera to maintain alignment of the x-ray source and the x-raycamera during a scanning mode in which the x-ray source and the x-raycamera move from one end of the object to another end, a motorcontrolled by the controller, a bi-directional crossover slide trackbearing assembly connected to the x-ray source, and a conveyoroperatively connected to the motor and to the slide track bearingassembly such that, responsive to actuation of the motor by thecontroller, the slide track bearing assembly moves in a loop thatcorrespondingly move the x-ray source and the x-ray camera along asingle linear axis.

With the objects in view, there is also provided a whole-bodytransmission x-ray scanner comprises a collimated x-ray source emittingx-rays, a linear x-ray camera configured to detect the x-rays, acontroller, and a positioner that aligns the x-ray source and the x-raycamera to point the emitted x-rays towards the x-ray camera and movesthe x-ray source and the x-ray camera synchronously to scan and acquireradiographic images of an object located between the x-ray source andthe x-ray camera, the positioner comprising a closed-loop cablealignment assembly fixed to the x-ray source and to the linear x-raycamera to maintain alignment of the x-ray source and the x-ray cameraduring a scanning mode in which the x-ray source and the x-ray cameramove from one end of the object to another end, a motor controlled bythe controller, a closed-loop, motor-controlled conveyor comprising afirst gear operatively connected to the motor, a second gear, and aroller chain wrapped around the first and second gears in a raceway, anda bi-directional crossover slide track bearing assembly connected to thex-ray source and comprising a flange fixed to a point of the rollerchain such that, responsive to actuation of the motor by the controller,the roller chain moves in a loop around the first and second gears andthe slide track bearing assembly correspondingly moves the x-ray sourcealigned with the x-ray camera along a single linear axis.

In accordance with another feature, the x-ray source comprises acollimator defining a slit to collimate the x-rays into a narrow fanbeam of x-rays and the linear x-ray camera comprises a linear array ofphotodiodes and is positioned to detect the fan beam of x-rays emittedfrom the collimator of the x-ray source throughout movement of the x-raysource along the axis.

In accordance with a further feature, the controller is anoperator-controlled computer having a user interface with controls tostart and stop the scanning mode and, during the scanning mode, create ascanned transmission x-ray image of the object disposed between thex-ray source and the x-ray camera responsive to scanning the x-raysacross the object.

In accordance with an added feature, the controller has a selectablemanual x-ray scanning mode and a continuous x-ray scanning mode.

In accordance with an additional feature, the computer forms anddisplays the scanned transmission x-ray image of the object on adisplay.

In accordance with yet another feature, the manual x-ray scanning modecomprises different manual scanning modes that selectively controlmovement speed of the x-ray source and the x-ray camera during movementalong the axis to alter an x-ray dose for different sizes of the objectbeing scanned.

In accordance with yet a further feature, the controller comprises adosimeter adjacent the x-ray camera and detecting the x-rays emitted andis configured to drive the conveyor with the motor at a variable speedautomatically adjustable to control the x-ray dose through thinner orthicker areas of the object being scanned.

In accordance with yet an added feature, the continuous x-ray scanningmode continuously drives the motor to continually move the x-ray sourceand the x-ray camera and the controller is configured to start x-rayemissions from the x-ray source when the x-ray camera is atapproximately the top of the axis and to stop x-ray emissions when thex-ray camera is at approximately the bottom of the axis.

In accordance with yet an additional feature, the controller displays anx-ray-on indicator while the x-rays are emitted and the controllerdisplays an x-ray-off indicator when the x-rays are not emitted.

In accordance with again another feature, the closed-loop cablealignment assembly remains in constant tension to move the linear x-raycamera in a synchronous motion that retains alignment of the x-rays withthe x-ray camera.

In accordance with again a further feature, the conveyor is aclosed-loop, motor-controlled conveyor belt system comprising a firstgear operatively connected to the motor, a second gear, and a rollerchain wrapped around the first and second gears in a raceway, and theslide track bearing assembly comprises a flange fixed to a point of theroller chain such that, responsive to movement of the roller chainaround the first and second gears, the slide track bearing assemblymoves the x-ray source and the x-ray camera along the axis.

In accordance with again an added feature, the first gear is one ofdirectly and indirectly connected to the motor.

In accordance with again an additional feature, the single linear axisis one of a vertical axis, a horizontal axis, and changeable between thevertical axis and the horizontal axis.

In accordance with still another feature, the object is a person.

In accordance with still a further feature, there is provided acounterweight assembly connected to at least one of the x-ray source,the x-ray camera, and the cable alignment assembly to balance a load ofthe x-ray source and the x-ray camera so that, when the x-ray source andx-ray camera move along the axis together, they present the sameresistance to the motor in either direction along the axis to reduceload-stress on the motor.

In accordance with still an added feature, the motor rotates in a singledirection during the scanning mode.

In accordance with still an additional feature, the positioner comprisesa slide-track assembly comprising a support tower connected to theconveyor, a track assembly connected to the x-ray camera, and a platformdisposed between the x-ray source and the x-ray camera on which theobject rests during an x-ray scan.

In accordance with another feature, there is provided a housingsurrounding the motor, the slide track bearing assembly, and theconveyor, and at least a portion of the positioner and defining apassageway in which the object enters and exits the housing.

In accordance with a concomitant feature, the x-ray source and the x-raycamera move in an x-ray plane and the raceway of the roller chain is inone of a plane parallel to the x-ray plane and a plane orthogonal to thex-ray plane.

Although the systems, apparatuses, and methods are illustrated anddescribed herein as embodied in a whole-body transmission x-ray scannerand methods for whole-body scanning, they are, nevertheless, notintended to be limited to the details shown because variousmodifications and structural changes may be made therein withoutdeparting from the spirit of the invention and within the scope andrange of equivalents of the claims. Additionally, well-known elements ofexemplary embodiments will not be described in detail or will be omittedso as not to obscure the relevant details of the systems, apparatuses,and methods.

Additional advantages and other features characteristic of the systems,apparatuses, and methods will be set forth in the detailed descriptionthat follows and may be apparent from the detailed description or may belearned by practice of exemplary embodiments. Still other advantages ofthe systems, apparatuses, and methods may be realized by any of theinstrumentalities, methods, or combinations particularly pointed out inthe claims.

Other features that are considered as characteristic for the systems,apparatuses, and methods are set forth in the appended claims. Asrequired, detailed embodiments of the systems, apparatuses, and methodsare disclosed herein; however, it is to be understood that the disclosedembodiments are merely exemplary of the systems, apparatuses, andmethods, which can be embodied in various forms. Therefore, specificstructural and functional details disclosed herein are not to beinterpreted as limiting, but merely as a basis for the claims and as arepresentative basis for teaching one of ordinary skill in the art tovariously employ the systems, apparatuses, and methods in virtually anyappropriately detailed structure. Further, the terms and phrases usedherein are not intended to be limiting; but rather, to provide anunderstandable description of the systems, apparatuses, and methods.While the specification concludes with claims defining the systems,apparatuses, and methods of the invention that are regarded as novel, itis believed that the systems, apparatuses, and methods will be betterunderstood from a consideration of the following description inconjunction with the drawing figures, in which like reference numeralsare carried forward.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying figures, where like reference numerals refer toidentical or functionally similar elements throughout the separateviews, which are not true to scale, and which, together with thedetailed description below, are incorporated in and form part of thespecification, serve to illustrate further various embodiments and toexplain various principles and advantages all in accordance with thesystems, apparatuses, and methods. Advantages of embodiments of thesystems, apparatuses, and methods will be apparent from the followingdetailed description of the exemplary embodiments thereof, whichdescription should be considered in conjunction with the accompanyingdrawings in which:

FIG. 1 is a fragmentary, side elevational and partially cross-sectionalview of an exemplary embodiment of a vertical scanning x-ray systemhaving an alignment cable loop assembly, a counterweight assembly, and avertical indexing-attachment-chain conveyor and bi-directional crossoverslide-track assembly that move an x-ray source and an x-ray camera inalignment with one another;

FIG. 2 is a side elevational and partially cross-sectional view of anx-ray source positioning system of the x-ray system of FIG. 1;

FIG. 3 is a side elevational and partially cross-sectional view of thex-ray source positioning system of FIG. 2 employing a single motor driveattached to a vertical indexing attachment chain conveyor andbi-directional crossover slide track assembly on the x-ray sourceassembly;

FIG. 4 is a fragmentary side elevational view of a portion of a verticalindexing-attachment-chain conveyor of FIG. 1 with a motor mountedindirectly to the conveyor;

FIG. 5 is a fragmentary, side elevational view of the verticalindexing-attachment-chain conveyor mounted with an x-ray source mountingplate to a support tower and with the motor mounted directly to theconveyor;

FIG. 6 is a side elevational view of an exemplary embodiment of aconnection between an x-ray source mounting plate and the verticalindexing-attachment-chain conveyor with a dovetail joint;

FIG. 7 is a fragmentary, side elevational view of a portion of anexemplary embodiment of the linear x-ray camera of FIG. 1 mounted to avertical track assembly and a camera mounting plate;

FIG. 8 is a simplified schematic diagram of an exemplary embodiment ofthe cable loop assembly of the x-ray scanner of FIG. 1 lifting the x-raysource and x-ray camera in alignment with one another;

FIG. 9 is a simplified schematic diagram of an exemplary embodiment ofthe cable loop assembly of the x-ray scanner of FIG. 1 lowering thex-ray source and x-ray camera in alignment with one another;

FIG. 10 is a fragmentary, side elevational view of an exemplaryembodiment of an x-ray source positioning portion of the x-ray scannerof FIG. 1;

FIG. 11 is a fragmentary, side elevational view of an exemplaryembodiment of an x-ray camera positioning portion of the x-ray scannerof FIG. 1;

FIG. 12 is a fragmentary, side elevational view of another exemplaryembodiment of a bi-directional crossover slide-track assembly in anorientation at an angle to the vertical indexing-attachment-chainconveyor for moving the x-ray source in alignment with an x-ray camera;

FIG. 13 is a fragmentary, side elevational view of another exemplaryembodiment of a vertical indexing-attachment-chain conveyor andbi-directional crossover slide-track assembly for moving the x-raysource with a flange centrally disposed in the verticalindexing-attachment-chain conveyor and moving downwards;

FIG. 14 is a fragmentary, side elevational view of the verticalindexing-attachment-chain conveyor and bi-directional crossoverslide-track assembly of FIG. 13 moving the flange upwards;

FIG. 15 is a fragmentary, side elevational and partially cross-sectionalview of an exemplary embodiment of a vertical scanning x-ray systemhaving a counterweight assembly and drive shaft driven, verticalindexing-attachment-chain conveyors with bi-directional crossoverslide-track assembly that respectively move an x-ray source and an x-raycamera in alignment with one another; and

FIG. 16 is a fragmentary, top plan view of an exemplary embodiment of adrive shaft system for the vertical indexing-attachment-chain conveyorsof FIG. 15.

DETAILED DESCRIPTION OF THE EMBODIMENTS

As required, detailed embodiments of the systems, apparatuses, andmethods are disclosed herein; however, it is to be understood that thedisclosed embodiments are merely exemplary of the systems, apparatuses,and methods, which can be embodied in various forms. Therefore, specificstructural and functional details disclosed herein are not to beinterpreted as limiting, but merely as a basis for the claims and as arepresentative basis for teaching one skilled in the art to variouslyemploy the systems, apparatuses, and methods in virtually anyappropriately detailed structure. Further, the terms and phrases usedherein are not intended to be limiting; but rather, to provide anunderstandable description of the systems, apparatuses, and methods.While the specification concludes with claims defining the features ofthe systems, apparatuses, and methods that are regarded as novel, it isbelieved that the systems, apparatuses, and methods will be betterunderstood from a consideration of the following description inconjunction with the drawing figures, in which like reference numeralsare carried forward.

In the following detailed description, reference is made to theaccompanying drawings which form a part hereof, and in which are shownby way of illustration embodiments that may be practiced. It is to beunderstood that other embodiments may be utilized and structural orlogical changes may be made without departing from the scope. Therefore,the following detailed description is not to be taken in a limitingsense, and the scope of embodiments is defined by the appended claimsand their equivalents.

Alternate embodiments may be devised without departing from the spiritor the scope of the invention. Additionally, well-known elements ofexemplary embodiments of the systems, apparatuses, and methods will notbe described in detail or will be omitted so as not to obscure therelevant details of the systems, apparatuses, and methods.

Before the systems, apparatuses, and methods are disclosed anddescribed, it is to be understood that the terminology used herein isfor the purpose of describing particular embodiments only and is notintended to be limiting. The terms “comprises,” “comprising,” or anyother variation thereof are intended to cover a non-exclusive inclusion,such that a process, method, article, or apparatus that comprises a listof elements does not include only those elements but may include otherelements not expressly listed or inherent to such process, method,article, or apparatus. An element proceeded by “comprises . . . a” doesnot, without more constraints, preclude the existence of additionalidentical elements in the process, method, article, or apparatus thatcomprises the element. The terms “including” and/or “having,” as usedherein, are defined as comprising (i.e., open language). The terms “a”or “an”, as used herein, are defined as one or more than one. The term“plurality,” as used herein, is defined as two or more than two. Theterm “another,” as used herein, is defined as at least a second or more.The description may use the terms “embodiment” or “embodiments,” whichmay each refer to one or more of the same or different embodiments.

The terms “coupled” and “connected,” along with their derivatives, maybe used. It should be understood that these terms are not intended assynonyms for each other. Rather, in particular embodiments, “connected”may be used to indicate that two or more elements are in direct physicalor electrical contact with each other. “Coupled” may mean that two ormore elements are in direct physical or electrical contact (e.g.,directly coupled). However, “coupled” may also mean that two or moreelements are not in direct contact with each other, but yet stillcooperate or interact with each other (e.g., indirectly coupled).

For the purposes of the description, a phrase in the form “A/B” or inthe form “A and/or B” or in the form “at least one of A and B” means(A), (B), or (A and B), where A and B are variables indicating aparticular object or attribute. When used, this phrase is intended toand is hereby defined as a choice of A or B or both A and B, which issimilar to the phrase “and/or”. Where more than two variables arepresent in such a phrase, this phrase is hereby defined as includingonly one of the variables, any one of the variables, any combination ofany of the variables, and all of the variables, for example, a phrase inthe form “at least one of A, B, and C” means (A), (B), (C), (A and B),(A and C), (B and C), or (A, B and C).

Relational terms such as first and second, top and bottom, and the likemay be used solely to distinguish one entity or action from anotherentity or action without necessarily requiring or implying any actualsuch relationship or order between such entities or actions. Thedescription may use perspective-based descriptions such as up/down,back/front, top/bottom, and proximal/distal. Such descriptions aremerely used to facilitate the discussion and are not intended torestrict the application of disclosed embodiments. Various operationsmay be described as multiple discrete operations in turn, in a mannerthat may be helpful in understanding embodiments; however, the order ofdescription should not be construed to imply that these operations areorder dependent.

As used herein, the term “about” or “approximately” applies to allnumeric values, whether or not explicitly indicated. These termsgenerally refer to a range of numbers that one of skill in the art wouldconsider equivalent to the recited values (i.e., having the samefunction or result). In many instances these terms may include numbersthat are rounded to the nearest significant figure. As used herein, theterms “substantial” and “substantially” means, when comparing variousparts to one another, that the parts being compared are equal to or areso close enough in dimension that one skill in the art would considerthe same. Substantial and substantially, as used herein, are not limitedto a single dimension and specifically include a range of values forthose parts being compared. The range of values, both above and below(e.g., “+/−” or greater/lesser or larger/smaller), includes a variancethat one skilled in the art would know to be a reasonable tolerance forthe parts mentioned.

It will be appreciated that embodiments of the systems, apparatuses, andmethods described herein may be comprised of one or more conventionalprocessors and unique stored program instructions that control the oneor more processors to implement, in conjunction with certainnon-processor circuits and other elements, some, most, or all of thefunctions of the systems, apparatuses, and methods described herein. Thenon-processor circuits may include, but are not limited to, signaldrivers, clock circuits, power source circuits, and user input andoutput elements. Alternatively, some or all functions could beimplemented by a state machine that has no stored program instructions,or in one or more application specific integrated circuits (ASICs) orfield-programmable gate arrays (FPGA), in which each function or somecombinations of certain of the functions are implemented as customlogic. Of course, a combination of these approaches could also be used.Thus, methods and means for these functions have been described herein.

The terms “program,” “software,” “software application,” and the like asused herein, are defined as a sequence of instructions designed forexecution on a computer system or programmable device. A “program,”“software,” “application,” “computer program,” or “software application”may include a subroutine, a function, a procedure, an object method, anobject implementation, an executable application, an applet, a servlet,a source code, an object code, any computer language logic, a sharedlibrary/dynamic load library and/or other sequence of instructionsdesigned for execution on a computer system.

Herein various embodiments of the systems, apparatuses, and methods aredescribed. In many of the different embodiments, features are similar.Therefore, to avoid redundancy, repetitive description of these similarfeatures may not be made in some circumstances. It shall be understood,however, that description of a first-appearing feature applies to thelater described similar feature and each respective description,therefore, is to be incorporated therein without such repetition.

Described now are exemplary embodiments. Referring now to the figures ofthe drawings in detail and first, particularly to FIG. 1, there is showna first exemplary embodiment of vertical scanning x-ray system 10comprising a bi-directional crossover slide-track assembly 100 and apositioner comprising a closed-loop, vertical indexing-attachment-chainconveyor 160, an alignment cable loop assembly 200, and a counterweightassembly 300. The slide-track assembly 100 moves an x-ray source 110 anda linear x-ray camera 120 with the cable loop assembly 200. Theslide-track assembly 100 comprises vertical support towers or rails 130,a vertical track assembly 140 for the x-ray camera 120, and a platform150 located between the towers 130 and the vertical track assembly 140.The platform 150 is elevated to provide a top surface at a height aboveground sufficient to allow the x-ray beam 112 to pass entirely throughthe feet of a person standing on the platform 150. The cable loopassembly 200 comprises a closed-looped cable 202 having a portiondefined as an outer cable 210 and a portion defined as an inner cable220 for reference with FIG. 1. The outer cable 210 is connected to amounting plate 116 of the x-ray source 110 and the inner cable 220 isconnected to a mounting plate 122 of the x-ray camera 120 through aplurality of pulleys 230. The configuration of the portions 210, 220 ofthe cable 202 attached to the mounting plates 116, 122 and the pulleys230 keeps the x-ray source 110 and the x-ray camera 120 aligned duringscanning movement as described in further detail below. Herein, theterms pulleys, sprockets, and gears are used. These terms are understoodto be broadly defined to not be limited to specific mechanicalstructures and, therefore, these terms are interchangeable where similarmechanical devices can perform the same function.

Movement of the x-ray source 110 occurs with a verticalindexing-attachment-chain conveyor 160 shown diagrammatically in FIGS. 2to 7. The conveyor 160 comprises a racetrack 162 (e.g., a roller chain)around a pair of sprockets, pulleys, or gears 164 that, together, movethe x-ray source 110 up and down when one of the gears 164 is driven bya motor 166. As the x-ray camera 120 is mechanically linked to the x-raysource 110 through the cable loop assembly 200, the x-ray camera 120also moves up and down, remaining vertically and horizontally alignedwith the x-ray source 110 and the x-ray beam 112 generated by the x-raysource 110. In this way, the x-ray beam 112, emitted by the x-ray source110 and passing through a collimator 114, passes through a stationary,standing person 11 on the platform 150 from the person's feet to the topof their head (or vice versa) in a single pass so that a whole-bodytransmission x-ray image can be acquired. In an exemplary embodiment, acounterweight assembly 300, comprising a counterweight 302, acounterweight cable 304, and counterweight pulleys 306, is connected tothe x-ray source 110 (or to the mounting plate 116) to relieve stress onthe motor 166 by offsetting some or all of the weight of the x-raysource 110 and/or the mounting plate 116 of the x-ray source 110. Morespecifically, the cable 302 is run through two counterweight pulleys 306and is fixed to the mounting plate 116, which, in turn, is fixed to thex-ray source 110. Alternatively and/or additionally, the counterweightcable 304 is connected to the x-ray camera 120 or to the mounting plate122 of the x-ray camera 120.

It is noted that the cable loop assembly 200 is depicted as running thecable 202, 210, 220 between the towers 130 and the track assembly 140over the top of the person 11. In an alternative non-illustratedconfiguration, the cable 202 can run below the towers 130 and the trackassembly 140, and/or the platform 150.

An exemplary embodiment of the x-ray source 110 suitable for securityapplications (e.g., contraband detection) is a mono-block x-raygenerator model number IXS 1650 manufactured by VJ X-Ray. Thismono-block x-ray generator can produce x-rays with an energy up toapproximately 160 KeV and a tube current up to approximately 8 mA.

The x-ray source 110 has an x-ray emission port (not shown) thatproduces a conical beam of x-rays with an emission cone angle of up toapproximately 40 degrees. The collimator 114 is mounted at the emissionport to collimate the conical beam down to a narrow horizontal fan beamof x-rays 112, which is suitable for a linear x-ray camera 120. A fanbeam is desired when scanning people to minimize x-ray exposure to theperson being scanned. The x-ray camera 120 has individual photodiodedetectors in a photodiode array. The detectors are disposed in a planehaving a width and a height. The plane is defined as the detector plane.The width of the detectors is substantially equal to a width of theentire photodiode array. The number of rows of detectors along the widthcan be a single row or it can be a number of parallel rows, depending onthe photodiode array used. In another exemplary embodiment, the x-raycamera has at least two series of diode arrays that allow imagesubtraction and allow dual imaging using a single x-ray beam source.Each diode array has a different scintillator which allows for imagesubtraction processing. In the exemplary embodiments, a size of thex-ray beam 112 has a height substantially equal to a height of the totalrows of the photodiode detectors of the x-ray camera 120. If thedetectors are aligned in a single row, the height of the x-ray beam isapproximately the height of the photodiode detector. The width of thex-ray beam 112 is substantially equal to a width of the photodiode arrayof the x-ray camera 120 in the detector plane. The exemplary embodimentof the size of the x-ray beam 112 minimizes the amount of x-rayradiation not impinging on the photodiode detectors. In alternativeexemplary embodiments, the x-ray beam 112 can extend outside the fieldof the photodiode detectors by a pre-set amount.

In an exemplary embodiment where the x-ray source is emitting x-rayswhen the system is powered on, the collimator 114 has a movable shieldthat blocks the x-ray beam 112 when x-ray scanning of a subject is notoccurring. In an exemplary embodiment of a normal operation, the x-raysource 110 is on when the system is powered on and emits x-rays whilepowered on but the x-ray source 110 is turned off when the system isidle for approximately 15 minutes. During this normal operation, a leadshutter (or other suitable x-ray shielding material) is moved over anoutput aperture defined by the collimator 114 to control emission ofx-rays that could expose the x-ray camera 120 (or persons in thevicinity of the system) when scanning is not desired.

Exemplary movement of the x-ray-source 110 is explained first withrespect to FIGS. 2 and 3. In this exemplary embodiment, the x-ray source110 is attached to a center of the x-ray mounting plate 116 (it can beoffset vertically or horizontally if desired). The motor 166 isconnected to one of the gears 164 of the verticalindexing-attachment-chain conveyor 160, either directly or through atransmission (e.g., a belt, a chain, a drive shaft, and/or a series ofgears, each of which are illustrated respectively in FIGS. 4 and 5. Themotor 166 in FIG. 5 is a direct drive motor and has an output shaftconnected to an axle of the gear 164, in this case a lower gear 164. Incontrast, the motor 166 in FIG. 4 is at a distance from the lower gear164 and the shaft of the motor 166 is connected to an axle of the gear164 through a transmission such as a belt or drive chain 167. Anexemplary embodiment of the motor 166 is a variable-speed gear motorCyclo 6000 (1-2 hp) manufactured by Sumitomo. Other motors such as servoor stepping motors can be used as well. In another exemplary embodiment,the motor is a variable-speed adjustable motor having the speedcontrolled by a controller 400. In such a configuration, the x-raysource (and the x-ray camera) can be made to travel faster or slowerthrough a particular part of the scanning area to control the x-ray beamdose, for example, through thinner or thicker areas of the object beingscanned. The speed can be adjusted by selecting a preset softwareapplication or by using a dosimeter to adjust the speed automaticallyduring the scan. An exemplary embodiment of the verticalindexing-attachment-chain conveyor 160 is a Roller Chain Conveyormanufactured by DirectConveyors.com and is capable of lifting severalhundred pounds. The exemplary embodiment of the verticalindexing-attachment-chain conveyor 160 comprises two gears 164, onemounted to the motor 166 and the other mounted on a rigid frame 168,illustrated in FIG. 1 and a portion of which is illustrated in dashedlines in FIG. 3. The roller chain 162 connects the two gears 164 to oneanother to form a racetrack. Accordingly, when the motor 165 rotates thelower gear 164, the racetrack of the roller chain 162 rotates. Fixed toa given location of the roller chain 162 is at least one bracket orflange 169. The flange 169 is further connected to a slide track bearingassembly 118 that, in turn, is connected to the mounting plate 116 ofthe x-ray source 110. As such, when the flange 169 moves around theracetrack as the roller chain 162 is driven by the motor 166, the flange169 moves the slide track bearing assembly 118 up and down (the flange169 also translates side-to-side approximately equal to a diameter ofthe gears 164). In other words, the flange 169 moves in a continuous orclosed loop, up and down and around the gears 164, as the motor 166drives the roller chain 162.

To not impart the same horizontal translation of the flange 169 to thex-ray source 110 as the flange 169 moves from one side of the gears 164to the other side, the slide track bearing assembly 118 is horizontallymovably connected to the mounting plate 116 of the x-ray source 110. Anexemplary embodiment of this movable connection is illustrated in FIGS.5 and 6. This movable connection positions a horizontal slot or groove117 on a side of the mounting plate 116 opposite the x-ray source 110(e.g., the rear side) and provides the slide track bearing assembly 118with a fixture that permits translating movement along the slot 117 butnot out of or orthogonal to the slot 117. One exemplary embodiment ofsuch a connection is a dovetail joint, which allows the slide trackbearing assembly 118 to slide horizontally back and forth from one sideof the gears 164 to the other as the flange 169 (along with the slidetrack bearing assembly 118) rotates around the gears 164 at both ends oftravel around the loop of the roller chain 162. FIG. 6 shows anexemplary embodiment of the flange-to-dovetail-joint connection. Theflange 169 is fixed to a first side of the slide track bearing assembly118 by a rod or bolt 119. The second side of the slide track bearingassembly 118 has a dovetail insert 115. In the exemplary embodimentshown in FIG. 5, the groove 117 in the mounting plate 116 for thedovetail joint is open only on one end (to the left in FIG. 5). Insteadof one blind end as illustrated, the other end also can be open. Eitheror both open ends of the dovetail joint can be closed by fixing aremovable spacer (not illustrated). The mounting plate 116 is movablyattached to the vertical towers 130 with respective bearings 132 thatallow the mounting plate 116 to move vertically along the towers 130 butremain laterally fixed in position with respect to the towers 130. Forexample, the towers 130 can be rods and the bearings 132 can be hollowpipes each respectively surrounding one of the rods. In this regard, themounting plate 116 remains precisely positioned both vertically andlaterally as it is driven up and down by the flange 169. In theembodiment of FIGS. 1 to 5, the towers 130 are mounted in a plane thatis parallel to a plane defined by the raceway of the roller chain 162.In FIG. 5, for example, the plane of the towers 130 is in front of andparallel to the plane of the raceway of the roller chain 162, which canbe seen by the connection of the slide track bearing assembly 118 inFIG. 6.

A linear x-ray camera mounting system 12 is shown in FIG. 7. The x-raycamera 120 is attached to the mounting plate 122 so that its lineararray of photodiodes faces the x-ray source 110 and is exposed to thenarrow fan-beam of x-rays 112. The mounting plate 122 is movablyattached to a set of vertical support posts 142 of the vertical trackassembly 140 with a set of bearings 144. The respective bearings 144allow the mounting plate 122 to move vertically along the support posts142 but remain laterally fixed in position with respect to the supportposts 142. For example, the support posts 142 can be rods and thebearings 144 can be hollow pipes each respectively surrounding one ofthe rods. In this regard, the mounting plate 122 remains preciselypositioned both vertically and laterally as it is driven up and down bythe cable 202. An example of the linear x-ray camera 120 that issuitable for security applications (e.g., contraband detection) islinear photodiode array model number XI8800-042-DR manufactured byX-Scan Corporation in San Jose, Calif. This camera has a single array ofphotodiodes each with an active area of 1.6 mm×2.4 mm. The length of thelinear array in accordance with an exemplary embodiment is 42 inches(106.7 mm) long. A pixelated scintillator made from Cesium Iodide dopedwith Thallium is attached to the photodiode array with a thickness of 4mm. The scintillator material absorbs x-rays that have passed throughthe body of the subject with high efficiency and converts the absorbedx-rays into a multitude of visible light photons that expose eachindividual photodiode detector to which it is attached. Each individualphotodiode in the diode array has its own block (with a dimension of 1.6mm×2.4 mm×4 mm) of scintillator material that is separated by a thinlayer of opaque material so that light emitted from each block ofscintillator material is confined to the photodiode to which it isattached. The length (nominally 0.9 to 1.07 meters) of the linear arrayis needed to span the entire width of the narrow fan beam of x-rays 112emitted by the x-ray source 110 when the source-to-camera distance isapproximately six feet and the cone angle is forty degrees. In thisexample of the linear photodiode array, therefore, the size of the x-raybeam 112 will have a height of no more than approximately 1.6 mm andwidth of no more than approximately 42 inches.

Referring now to FIGS. 8 and 9, the cabling system is shown without thesupporting structure and with the pulleys 230 in a simplifiedconfiguration as compared to FIG. 1 for reasons of clarity. As in FIG.1, the cable loop assembly 200 is guided around the pulleys 230 to forma single raceway. The mounting plate 116 of the x-ray source 110 isfixed to the outer cable 210 (see FIG. 1) and the x-ray camera 120 isfixed to the inner cable 220 (see FIG. 1). With the conveyor 160 drivingthe x-ray source 110 as described herein, when the x-ray source 110 ismoved upwards as shown with the solid arrow in FIG. 8, the x-ray camera120 that is positioned directly across from the exit of the collimator114 is moved correspondingly (dashed arrow) to have the beam of x-rays112 directly impact the detectors of the photodiode array throughoutthat upwards movement. Likewise, when the x-ray source 110 is moveddownwards as shown by the solid arrow in FIG. 9, the x-ray camera 120that is positioned directly across from the exit of the collimator 114is moved correspondingly (dashed arrow) to have the beam of x-rays 112directly impact the detectors of the photodiode array throughout thatdownwards movement.

FIGS. 10 and 11 illustrate how the configuration of the cable loopassembly 200, the pulleys 230, the support towers 130, and the verticaltrack assembly 140 keep the x-ray source 110 an the x-ray camera 120aligned at all times. This orientation is from the point of view of theperson 11 standing on the platform 150. In FIG. 10, the view is from theperson 11 on the platform 150 looking at the x-ray source 110. In thisview, the x-ray source 110 and the collimator 114 point directly at theperson being scanned. Cable fasteners 170 attach the outer cable 210 tothe mounting plate 116 of the x-ray source 110. Support brackets 180attach the pulleys 230 to the support towers 130. In FIG. 11, the viewis from the person 11 on the platform 150 looking at the x-ray camera120. In this view, the x-ray camera 120 faces the person being scanned.In this view, cable fasteners 172 attach the inner cable 220 to themounting plate 122 of the x-ray camera 120. Support brackets 180 attachthe pulleys 230 to the track assembly 140.

FIG. 12 shows another exemplary embodiment of the verticalindexing-attachment-chain conveyor 160. In this configuration, the planedefined by the raceway of the roller chain 162 is perpendicular to theplane defined by the support towers 130. The slide track bearingassembly 118 shown in FIG. 5 connected to the mounting plate 116 isreplaced with a slide track bearing assembly 260 having parts, at leastone connected to the mounting plate 166 and at least one connected tothe roller chain 162. This slide track bearing assembly 260 movesperpendicular to the mounting plate 116, i.e., in the plane of FIG. 12.In this embodiment, a slide track bearing 262 connected to the rollerchain 162 is movably disposed on a slide bar 264 that is fixed to themounting plate 116 and projects away from the side of the mounting plate116 opposite the x-ray source 110 (e.g., referred to as the rear side).The slide track bearing 262 is connected to the flange 169 on the rollerchain 162 at a distance (in other words, the plane of the raceway of theroller chain 162 is parallel to the line defined by the bearing bar264). As can be seen in the two positions of the x-ray source 110 inFIG. 12 (one upper and one lower), the slide track bearing 262 connectedto the roller chain 162 on the left is moving upwards on the racetrackof the conveyor 160 (dashed arrow A) and will move to the right when ittravels around the upper gear 164. During this upwards movement, theslide track bearing 262 raises the bearing bar 264 (and the x-ray source110). As the slide track bearing 262 moves around the upper gear 164,the slide track bearing 262 travels along a horizontal distance. Duringthis time, the slide track bearing 262 slides (to the right) along thebearing bar 264 in the plane perpendicular to the towers 130. During thetravel from the upper gear 164 towards the lower gear 164, the slidetrack bearing 262 moves downwards on the racetrack of the conveyor 160(dashed arrow B) and lowers the bearing bar 264 (along with the x-raysource 110). When the slide track bearing 262 travels around the lowergear 164, the slide track bearing 262 moves along a horizontal distance(to the left), during which time the slide track bearing 262 slidesalong the bearing bar 264 to the left in the plane perpendicular to thetowers 130.

FIGS. 13 and 14 show yet another exemplary embodiment of the verticalindexing-attachment-chain conveyor 160. In this configuration, the planeof the racetrack formed by the gears 164 and the roller chain 162 isparallel to the planes of the towers 130 and the plane of the mountingplate 116 as in the configuration of FIG. 5. The difference in thisconfiguration from the one in FIG. 5, for example, is that the flange169 is mounted on the roller chain 2 and projects into the interior ofthe racetrack and in the plane of the racetrack. The point at which theflange 169 connects to the mounting plate 116 is along a line centeredwith respect to the roller chain 162 and the gears 164. Along thiscenter line is the rigid frame 168 upon which the gears 164 and theflange 169 are mounted. The frame 168 is fixed with respect to thetowers 130 but this fixation structure is not illustrated in thesefigures. The upper and lower gears 164 are fixed in all three lateraldimensions but are rotationally free with respect to the frame 168 sothat the gears 164 can rotate. Accordingly, when the motor 166rotationally drives, e.g., the lower gear 164, the roller chain 162moves around the racetrack and rotates the upper gear 164. As a firstside/end of the flange 169 is fixed to a point 163 on the roller chain162, the flange 169 travels around the raceway as the roller chain 162moves. The other side/end of the flange 169 is fixed to a bearing 134that is connected to the side of the mounting plate 116 opposite thex-ray source 110 (e.g., referred to as the rear side). This bearing 134is able to slide up and down the frame 168 between the axles of thegears 164 but is fixed to the inner end of the flange 169 that isopposite the outer end fixed to the roller chain 162. At this inner end,the flange 169 and the bearing 134 are fixed but are rotationally freelyconnected. Accordingly, motion of the outer end of the flange 169follows, e.g., the dashed arrows C and D in FIGS. 13 and 14 when theroller chain 162 revolves in a clockwise direction and the motion of thebearing 134 follows the direction of arrows E and F, respectively. Theform of the frame 168 between the axles of the gears 164 can take anyshape. In one exemplary embodiment, the frame 168 is a rod with a givendiameter and the bearing 134 is a rod having an outer diameter largerthan the given diameter and having a throughbore with a diametersubstantially equal to or slightly larger than the given diameter sothat the bearing can translate up and down the rod of the frame 168.Another exemplary embodiment of the frame 168 is a beam having a centralvertical slot and of the bearing 134 is a rod having a thickened portionextending to the mounting plate 116, an intermediate, narrowed portionwithin the central vertical slot, and a thickened head on the other sideof the beam of the frame 168. In each of the exemplary embodiments, theflange 169 can rotate with respect to the bearing 134 as it travelsaround the raceway and the bearing 134 can move vertically up and downalong the frame 168 to translate the mounting plate 116 between anuppermost location of the x-ray source 110 (defining a top of a scan)and a lowermost location of the x-ray source 100 (defining a bottom ofthe scan). It is noted that the frame 168 can be disposed between theplane of the raceway of the roller chain 162 and the plane of the towers130 or at a side of (to the rear of) the roller chain 162 opposite themounting plate 116.

FIGS. 15 and 16 illustrate yet another exemplary embodiment of thevertical scanning x-ray system 10. In this exemplary configuration, thex-ray source 110 and the x-ray camera 120 each have their own verticalindexing-attachment-chain conveyors 160 (each with a slide track bearingassembly 118). A single motor 166 drives both of the conveyors 160through a single drive shaft 272. As shown in the exemplary embodimentof FIG. 16, the output shaft 165 of the motor 166 is connected to adriver 163 (which can be a gear, a transmission, a belt, or any othersimilar mechanism) that is connected to the drive shaft 272. This driveshaft 272, in turn, is connected through other drivers 163 to respectiveshafts 161 on the conveyors 160 to rotate the conveyors 160 and move thex-ray source 110 and the x-ray camera 120 together in alignment. Becauseboth conveyors 160 are driven simultaneously with a single drive, thecable loop assembly 200 is no longer needed and, therefore, is notpresent. In the exemplary embodiment, the drive shaft 272 is connecteddirectly to the conveyors 160. Alternatively, the drive shaft 272 can beconnected indirectly through a transmission (e.g., a belt). The x-raysource 110 and the x-ray camera 120 are both moved by the same motorassembly keeping them always aligned during scanning procedures.

In another exemplary embodiment, the x-ray scanner comprises a secondx-ray source and a second linear x-ray camera that is installed ninetydegrees from the first x-ray source and the first linear x-ray camera tocreate a 3D simulation image. The second x-ray source and the secondx-ray camera are controlled by the same motor drive as the first x-raysource and first linear x-ray camera and additional alignment cables areadded to drive the second x-ray source and second x-ray camera.

The embodiments of the vertical scanning x-ray systems and methodsdescribed and shown herein are illustrated without any housing. In use,these scanners can be enclosed with walls and appropriate covers thatdefine a passageway through which each subject to be scanned will enterand exit the scanning area over the platform 150. The covers can beconfigured to allow the subject to enter the passageway in a singledirection and exit in another (e.g., opposite) direction or they can beconfigured to allow the subject to enter and exit the scanning area inthe same direction. The covers can be x-ray opaque in various locationsto inhibit or prevent stray x-ray radiation from escaping the housing.

Control of the scanning can occur with controller 400 having at leastone processor. The Controller is illustrated diagrammatically in FIG. 1.The controller 400 has a user interface connected to the at least oneprocessor to allow operators, for example, to register persons beingscanned into a database and to control any and all aspects of the x-raysource 110, the linear x-ray camera 120, the collimator 114, and themotor 166 to acquire images and display those images for analysis. Apersonal computer can be used as the processor and/or user interfacewith at least one controlling software application. The x-ray source 110and the x-ray camera 120 have communication ports, such as USB or serialports (RS-232), so that they can be controlled from the computerprogram. Motor controllers (e.g., the processor(s)) can be used toprovide remote control, through a computer interface, to almost any typeof motor commercially available.

In accordance with another exemplary embodiment of the scanner, theperson being imaged can lay horizontally on a table instead of standingon a platform. In such a case, the positioning system is rotated ninetydegrees from that shown and described herein so that the x-ray source110 moves laterally in a plane parallel to the table top and the x-raycamera 120 moves underneath the table top. The supporting tower 130 andtrack assembly 140 are, then mounted in a fixed horizontal plane thatdoes not need a counterweight assembly. In another exemplaryconfiguration, the supporting tower 130, the track assembly 140, and thecable loop assembly 200 could be mounted in a structure that is rotatedfrom a person-standing position (i.e., vertical) to a lay-down position(i.e., horizontal).

In accordance with yet another exemplary embodiment of the scanningx-ray system, the vertical indexing-attachment-chain conveyor 160 ismounted horizontally and the track assembly 140 is mounted horizontally.In this configuration, the x-ray source 110 produces a vertical fan beamof x-rays that is further collimated into a narrow fan beam of x-rays112 oriented vertically that sweeps laterally back and forth.Correspondingly, the linear x-ray camera 120 is also rotated to avertical position. The cable loop assembly 200 along with the supportrails 130 and track assembly 140 are also mounted horizontally to allowthe x-ray source 110 and the x-ray camera 120, respectively, to panlaterally across a stationary object or person. The x-ray camera 120 inthis configuration is long enough to capture an image of an entireperson, in other words, about 80 inches (203 cm) long.

For security screening applications the x-ray source 110 and the x-raycamera 120 as described herein provide suitable exposure dose and imagequality. For other applications such as medical diagnostics, the x-raysource 110 increases output power and the x-ray camera 120 has smallerpixel sizes to provide the image quality needed for medical diagnostics.An example of such an x-ray source 110 is one that has a power output inthe approximately 10 kW to 50 kW range and the x-ray camera 120 needs apixel size of greater than or equal to approximately 0.2 mm.

Manual Scanning Mode

For manual scanning, the system operates in a single cycle mode. Theperson is positioned in an x-ray scan position indicated, for example,by an outline image of two feet on the floor at a shoulder width apart.The operator starts the scan from an operator control station. Theconveyors start moving and, once the x-ray source and x-ray camera arein a position to start a scan (e.g., at the top of the scanning area),the x-ray beam is engaged and the x-ray scan of the person begins andcontinues until the source/camera reach a bottom of the scan area, atwhich time the x-ray beam is turned off. The x-ray source and x-raycamera continue to a home position and stop and do not proceed until theoperator starts the next scan. One example of the home position is atthe bottom of the conveyor. In this position, the speed of the x-raysource and x-ray camera will be constant by the time that a scan startsfrom the top of the conveyor and stops at the bottom of the conveyor.Another example of the home position is at a position in theintermediate extent of the conveyor. In this position, the speed of thex-ray source and x-ray camera will be constant by the time that a scanstarts from either the top of the conveyor and stops at the bottom ofthe conveyor or the bottom of the conveyor and stops at the top of theconveyor.

Continuous Scanning Mode

In a continuous scanning mode, the system operates continuously but onlyallows x-rays to travel to the camera when a person is present in thescanning area. In this mode, at the scan of a first person, the operatorhas the first person enter the x-ray scanning area and stand in ascanning position, e.g., indicated by images of two feet on the floor.The operator starts the continuous scan mode and follows the manualscanning mode procedures. Once the x-ray scan of that person iscomplete, that person leaves the scanning area and the next personenters the scanning area, assumes the scanning position, and waits forthe scan to begin and end. The system does not park but, instead,continues to operate in this mode until the operator stops the scanningprocess. In the continuous scanning mode, therefore, the conveyor movesthe x-ray source and x-ray camera continuously up and down, e.g., at aconstant rate, and each respective person is scanned with x-rays fromtop-to-bottom or from bottom-to-top.

The system operator can select a manual single scan mode from a menuand, in an exemplary embodiment, select different scanning modes thatcontrol the speed of the x-ray source and the x-ray camera for differentsizes of people allowing increased x-ray dose for larger persons (slowerspeed) and lower x-ray dose for smaller persons (faster speed). Thesystem operator also has an option for the continuous scanning mode. Asset forth above, in the continuous scanning mode, the system motor driveassembly continues moving and the x-ray scan starts when the x-raysource and the x-ray camera are in start scan position (which can be atthe top of the rotation of the conveyor belt/chain). An x-ray-onindicator (e.g., a red light) is illuminated when the x-ray beam isactive. Once the scan is complete, the x-ray-on indicator turns off andan x-ray-off indicator (e.g., a green light) is illuminated to allow theperson who was just scanned to exit and give time for the next person tobe scanned to enter and position themselves before the x-ray-onindicator is illuminated and when x-ray beam reactivates.

It is noted that various individual features of the inventive processesand systems may be described only in one exemplary embodiment herein.The particular choice for description herein with regard to a singleexemplary embodiment is not to be taken as a limitation that theparticular feature is only applicable to the embodiment in which it isdescribed. All features described herein are equally applicable to,additive, or interchangeable with any or all of the other exemplaryembodiments described herein and in any combination or grouping orarrangement. In particular, use of a single reference numeral herein toillustrate, define, or describe a particular feature does not mean thatthe feature cannot be associated or equated to another feature inanother drawing figure or description. Further, where two or morereference numerals are used in the figures or in the drawings, thisshould not be construed as being limited to only those embodiments orfeatures, they are equally applicable to similar features or not areference numeral is used or another reference numeral is omitted.

The foregoing description and accompanying drawings illustrate theprinciples, exemplary embodiments, and modes of operation of thesystems, apparatuses, and methods. However, the systems, apparatuses,and methods should not be construed as being limited to the particularembodiments discussed above. Additional variations of the embodimentsdiscussed above will be appreciated by those skilled in the art and theabove-described embodiments should be regarded as illustrative ratherthan restrictive. Accordingly, it should be appreciated that variationsto those embodiments can be made by those skilled in the art withoutdeparting from the scope of the systems, apparatuses, and methods asdefined by the following claims.

What is claimed is:
 1. A whole-body transmission x-ray scanner,comprising: a collimated x-ray source emitting x-rays; a linear x-raycamera configured to detect the x-rays; a controller; and a positionerthat aligns the x-ray source and the x-ray camera to point the emittedx-rays towards the x-ray camera and moves the x-ray source and the x-raycamera synchronously to scan and acquire radiographic images of anobject located between the x-ray source and the x-ray camera, thepositioner comprising: a closed-loop cable alignment assembly fixed tothe x-ray source and to the linear x-ray camera to maintain alignment ofthe x-ray source and the x-ray camera during a scanning mode in whichthe x-ray source and the x-ray camera move from one end of the object toanother end; a motor controlled by the controller; a bi-directionalcrossover slide track bearing assembly connected to the x-ray source;and a conveyor operatively connected to the motor and to the slide trackbearing assembly such that, responsive to actuation of the motor by thecontroller, the slide track bearing assembly moves in a loop thatcorrespondingly move the x-ray source and the x-ray camera along asingle linear axis.
 2. The scanner according to claim 1, wherein: thex-ray source comprises a collimator defining a slit to collimate thex-rays into a narrow fan beam of x-rays; and the linear x-ray cameracomprises a linear array of photodiodes and is positioned to detect thefan beam of x-rays emitted from the collimator of the x-ray sourcethroughout movement of the x-ray source along the axis.
 3. The scanneraccording to claim 1, wherein the controller is an operator-controlledcomputer having a user interface with controls to start and stop thescanning mode and, during the scanning mode, create a scannedtransmission x-ray image of the object disposed between the x-ray sourceand the x-ray camera responsive to scanning the x-rays across theobject.
 4. The scanner according to claim 3, wherein the controller hasa selectable manual x-ray scanning mode and a continuous x-ray scanningmode.
 5. The scanner according to claim 3, wherein the computer formsand displays the scanned transmission x-ray image of the object on adisplay.
 6. The scanner according to claim 4, wherein the manual x-rayscanning mode comprises different manual scanning modes that selectivelycontrol movement speed of the x-ray source and the x-ray camera duringmovement along the axis to alter an x-ray dose for different sizes ofthe object being scanned.
 7. The scanner according to claim 6, whereinthe controller comprises a dosimeter adjacent the x-ray camera anddetecting the x-rays emitted and is configured to drive the conveyorwith the motor at a variable speed automatically adjustable to controlthe x-ray dose through thinner or thicker areas of the object beingscanned.
 8. The scanner according to claim 4, wherein the continuousx-ray scanning mode continuously drives the motor to continually movethe x-ray source and the x-ray camera and the controller is configuredto start x-ray emissions from the x-ray source when the x-ray camera isat approximately the top of the axis and to stop x-ray emissions whenthe x-ray camera is at approximately the bottom of the axis.
 9. Thescanner according to claim 8, wherein the controller displays anx-ray-on indicator while the x-rays are emitted and the controllerdisplays an x-ray-off indicator when the x-rays are not emitted.
 10. Thescanner according to claim 1, wherein the closed-loop cable alignmentassembly remains in constant tension to move the linear x-ray camera ina synchronous motion that retains alignment of the x-rays with the x-raycamera.
 11. The scanner according to claim 1, wherein: the conveyor is aclosed-loop, motor-controlled conveyor belt system comprising: a firstgear operatively connected to the motor; a second gear; and a rollerchain wrapped around the first and second gears in a raceway; and theslide track bearing assembly comprises a flange fixed to a point of theroller chain such that, responsive to movement of the roller chainaround the first and second gears, the slide track bearing assemblymoves the x-ray source and the x-ray camera along the axis.
 12. Thescanner according to claim 11, wherein the first gear is one of directlyand indirectly connected to the motor.
 13. The scanner according toclaim 1, wherein the single linear axis is one of: a vertical axis; ahorizontal axis; and changeable between the vertical axis and thehorizontal axis.
 14. The scanner according to claim 1, wherein theobject is a person.
 15. The scanner according to claim 1, which furthercomprises a counterweight assembly connected to at least one of thex-ray source, the x-ray camera, and the cable alignment assembly tobalance a load of the x-ray source and the x-ray camera so that, whenthe x-ray source and x-ray camera move along the axis together, theypresent the same resistance to the motor in either direction along theaxis to reduce load-stress on the motor.
 16. The scanner according toclaim 1, wherein the motor rotates in a single direction during thescanning mode.
 17. The scanner according to claim 1, wherein thepositioner comprises a slide-track assembly comprising a support towerconnected to the conveyor, a track assembly connected to the x-raycamera, and a platform disposed between the x-ray source and the x-raycamera on which the object rests during an x-ray scan.
 18. The scanneraccording to claim 1, further comprising a housing surrounding themotor, the slide track bearing assembly, and the conveyor, and at leasta portion of the positioner and defining a passageway in which theobject enters and exits the housing.
 19. The scanner according to claim11, wherein the x-ray source and the x-ray camera move in an x-ray planeand the raceway of the roller chain is in one of: a plane parallel tothe x-ray plane; and a plane orthogonal to the x-ray plane.
 20. Awhole-body transmission x-ray scanner, comprising: a collimated x-raysource emitting x-rays; a linear x-ray camera configured to detect thex-rays; a controller; and a positioner that aligns the x-ray source andthe x-ray camera to point the emitted x-rays towards the x-ray cameraand moves the x-ray source and the x-ray camera synchronously to scanand acquire radiographic images of an object located between the x-raysource and the x-ray camera, the positioner comprising: a closed-loopcable alignment assembly fixed to the x-ray source and to the linearx-ray camera to maintain alignment of the x-ray source and the x-raycamera during a scanning mode in which the x-ray source and the x-raycamera move from one end of the object to another end; a motorcontrolled by the controller; a closed-loop, motor-controlled conveyorcomprising: a first gear operatively connected to the motor; a secondgear; and a roller chain wrapped around the first and second gears in araceway; and a bi-directional crossover slide track bearing assemblyconnected to the x-ray source and comprising a flange fixed to a pointof the roller chain such that, responsive to actuation of the motor bythe controller, the roller chain moves in a loop around the first andsecond gears and the slide track bearing assembly correspondingly movesthe x-ray source aligned with the x-ray camera along a single linearaxis.